RICHARD JAY WALDINGER is a computer science researcher at SRI
International 's
Artificial Intelligence CenterArtificial Intelligence Center (where he has worked
since 1969) whose interests focus on the application of automated
deductive reasoning to problems in software engineering and artificial
intelligence .

In his thesis (
Carnegie Mellon UniversityCarnegie Mellon University , 1969), which concerned
the extraction of computer programs from proofs of theorems, he found
that the application of the resolution rule accounted for the
appearance of a conditional branch in the extracted program, while the
use of the mathematical induction principle caused the introduction of
recursion and other repetitive constructs.

CAREER

Waldinger started at SRI International, then known as the Stanford
Research Institute, in 1969, and has remained there since then. He has
served coffee and cookies in his office at SRI twice a week since
1970.

QA4

Waldinger collaborated with Cordell Green, Robert Yates, Jeff
Rulifson, and Jan Derksen on QA4 , a PLANNER -like artificial
intelligence language geared towards automatic planning and theorem
proving. QA4 introduced the notion of context and also of
associative-commutative unification, which made the associative and
commutative axioms for operators not only unnecessary but also
inexpressible. They applied the language to planning for the SRI
robot, Shakey . With Bernie Elspas and Karl Levitt, Waldinger used QA4
for program verification (proving that a program does what it's
supposed to), obtaining automatic verifications for the unification
algorithm and Hoare 's FIND program.

PROGRAM SYNTHESIS

While Waldinger's thesis had dealt with the synthesis of applicative
programs, which return an output but produce no side effects,
Waldinger then turned to the synthesis of imperative programs, which
do both. To deal with the problem of achieving simultaneously goals
that interfere with each other, he introduced the notion of goal
regression, which was obtained from earlier work in program
verification by Floyd , King, Hoare , and Dijkstra . Since imperative
programs are analogous to plans, the approach was also applicable to
classical AI planning problems.

In collaboration with
Zohar Manna , of
Stanford UniversityStanford University ,
Waldinger developed nonclausal resolution, a form of resolution that
did not require the translation of logical sentences into a restricted
clausal form. Not only was the translation expensive, but also it
sometimes pathologically complicated the proof of the resulting
theorem; these problems were circumvented by the new rule. They
applied the rule on paper to produce a detailed synthesis of a
unification algorithm. In a separate paper, they synthesized a novel
square-root algorithm; they found that the notion of binary search
appears spontaneously by a single application of the resolution rule
to the specification of the square root.

SNARK

Some of Manna and Waldinger's theorem proving ideas were incorporated
into the design of Mark Stickel's
SNARK theorem prover . NASA
researchers, led by Mike Lowry, used SNARK in the implementation of
the software-development environment Amphion, which has been used to
construct programs to analyze data from
NASANASA missions for planetary
astronomers. Software constructed automatically by Amphion has been
used to plan photography for the
Cassini-HuygensCassini-HuygensNASANASA mission; this is
perhaps the most practical application to date of software constructed
automatically by deductive methods.

The SNARK system has been incorporated by the Kestrel Institute into
their software development environment Specware, which has been used
by Waldinger for the validation of the first-order axiomatization of
DAML , the
DARPADARPA agent markup language, and its successor, OWL . SNARK
uncovered inconsistencies not only in the axioms for DAML, but also in
the axioms for the foundational language KIF , on which the DAML
axiomatization was based. Recently, Waldinger has worked on the
application of deductive methods to answer questions in geography,
biology, and intelligence analysis. In collaboration with the Kestrel
Institute, he has been using SNARK to authenticate security protocols.

MEMBERSHIPS AND AWARDS

In 1991, Waldinger was elected as a fellow of the Association for the
Advancement of Artificial Intelligence .

PERSONAL LIFE

In his personal life, Waldinger is a student of aikido, yoga, and
meditation. A member of an established writing group, he has published
food journalism and erotic fiction. He is married and has two
children and three grandchildren.